Dental attachment assembly cap and method of use

ABSTRACT

A dental attachment assembly and method anchors a dental appliance with an implant and has an abutment member attached to the implant, a retention member in releasable snap engagement with the abutment member, and a cap secured in a recess of the dental appliance and in releasable swivel engagement with the retention member to position and secure the dental appliance onto the implant. The cap includes a cavity with a rounded, concave inner surface which engages with the retention member, an interior top surface of the cavity with a concave recess extending radially along an outer periphery of the interior top surface of the cavity to allow for rotation of the retention member within the cap. A central portion of the interior top surface of the cavity surrounded by the concave recess therefore protrudes vertically into the cavity to minimize vertical displacement of the retention member as it rotates.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 14/715,475filed on May 18, 2015, which is a continuation of application Ser. No.14/298,818 filed on Jun. 06, 2014 which issued on as U.S. Pat. No.9,033,709 on May 19, 2015. The contents of each of the aforementionedapplications are incorporated herein by reference in their entirety.

BACKGROUND Field of the Invention

Devices and methods provided herein relate to a dental attachmentassembly for anchoring a dental appliance with a base structure such asa dental implant, and more specifically to an attachment assembly with acap for positioning and retaining the dental appliance.

Related Art

Dental anchoring assemblies are known in which a female part is providedfor attachment to a root, implant, or adjacent tooth, and a male part isengaged in a recess in a dental appliance, the male and female partshaving mating, snap engageable formations for releasably securing themale part to the female part. For example, in U.S. Pat. No. 5,417,570,to Zuest, the female part has a socket and the male part has a head forsnap engagement in the socket. However, users may find it difficult toproperly locate the male head in the female socket, such that the headmay hit the periphery of the socket in some cases. Repeated impacts ofthis nature may damage the retentive head of the male, causing it tolose some of its retention ability.

U.S. Pat. Nos. 6,030,219 and 6,299,447 of Zuest et al., incorporatedherein by reference in their entirety, describe dental attachmentassemblies in which the male part has a skirt for snap engagement overan outer locating surface of the female or abutment member. The malepart may also have a central stem for snap engagement in a socket in thefemale part, providing both inner and outer retention surfaces, andtherefore increased retention force. It is also easier to locate themale part properly over the female part.

U.S. Pat. No. 6,981,871, to Zuest, incorporated herein by reference inits entirety, describes an outer locating surface that has at least twoaxially spaced retention surfaces for mating, snap engagement withcorresponding spaced snap engagement formations on the inner surface ofa cap secured in a dental appliance to provide a stacked, externalretention between the abutment and retention members.

However, it is desirable to not only improve the retention of thecomponents of the dental attachment assemblies but to also improve theiradjustability.

SUMMARY

Embodiments described herein provide for a dental attachment assemblyand method which anchors a dental appliance with an implant or otherbase structure, the dental attachment assembly including an abutmentmember attached to the implant or base structure, a retention member inreleasable snap engagement with the abutment member, and a cap securedin a recess of the dental appliance and configured in releasable swivelengagement with the retention member to position and secure the dentalappliance onto the implant. The cap includes a cavity with a rounded,concave inner surface which engages with the retention member, and aninterior top surface of the cavity with a concave recess extendingradially along an outer periphery of the interior top surface of thecavity to allow for rotation of the retention member within the cap. Acentral portion of the interior top surface of the cavity surrounded bythe concave recess therefore protrudes vertically into the cavity tominimize vertical displacement of the retention member as it rotateswithin the cap.

In one embodiment, a cap of a dental attachment assembly comprises anouter surface shaped to engage with a recess in a dental appliance; arounded, concave inner surface defining a cavity to receive a swivelengagement with a retention member; and an interior top surface of thecavity with a concave recess extending radially along an outer peripheryof the interior top surface of the cavity.

In a further embodiment, a dental attachment assembly comprises anabutment member with a first end shaped to attach to a tooth root,implant or adjacent tooth, and a second end with an outer locatingsurface; a retention member having a first end and a skirt extendingfrom the first end defining an inner surface for engagement over theouter locating surface of the abutment member; and a cap with a rounded,concave inner surface defining a cavity to receive a swivel engagementwith the retention member; wherein an interior top surface of the cavityincludes a concave recess extending radially along an outer periphery ofthe interior top surface of the cavity.

Other features and advantages of the present invention will become morereadily apparent to those of ordinary skill in the art after reviewingthe following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and operation of the present invention will be understoodfrom a review of the following detailed description and the accompanyingdrawings in which like reference numerals refer to like parts and inwhich:

FIG. 1A is a side cutout view of a dental attachment assembly, accordingto an embodiment of the invention;

FIG. 1B is an isometric view illustration of the cap of the dentalattachment assembly, according to one embodiment of the invention;

FIG. 1C is an isometric cutout view illustration of the cap of thedental attachment assembly, according to one embodiment of theinvention;

FIG. 2 is a side cutout view illustration of a cap and retention memberof the dental attachment assembly, according to an embodiment of theinvention;

FIG. 3 is a side cutout view illustration of the cap illustratingconsecutive tangent circle arcs which are used to create an angle of aconcave recess on an interior wall of the cap, according to anembodiment of the invention;

FIG. 4 is a side cutout view illustration of the cap illustrating anangle of the concave recess, according to an embodiment of theinvention;

FIG. 5 is a side cutout view of a dental attachment assembly in a fullyswiveled position, according to an embodiment of the invention;

FIG. 6 is a side cutout view illustration of a progression of theretention member swiveling from an un-swiveled position to a fullyswiveled position, according to an embodiment of the invention;

FIG. 7 is a side view illustration of the dental attachment assembly ina fully swiveled position, according to an embodiment of the invention;

FIG. 8 is a side cutout view illustration of the cap and an alternatedesign of the retention member and an alternate design of an abutment,according to an embodiment of the invention;

FIG. 9 is a side cutout view illustration of the cap and an alternatedesign of the retention member and an abutment, according to anembodiment of the invention;

FIGS. 10A and 10B are side-by-side comparisons of diameters of circleswhich define an outer surface of two configurations of the retentionmembers, according to an embodiment of the invention;

FIG. 11 is a side cutout view illustration of a different-sizedconfiguration of the dental attachment assembly, according to anembodiment of the invention;

FIG. 12 is a side view illustration of the different-sized configurationof the dental attachment assembly in a fully swiveled position,according to an embodiment of the invention;

FIG. 13 is a flow diagram illustrating an example process for anchoringa dental appliance in a patient's mouth, according to an embodiment ofthe invention;

FIG. 14 is a side view illustration of the dental attachment assemblyafter securing the dental appliance in a patient's mouth, according toan embodiment of the invention; and

FIG. 15 is a side view illustration of the process of anchoring the capand retention member onto the abutment of the dental attachmentassembly, according to an embodiment of the invention.

DETAILED DESCRIPTION

Certain embodiments disclosed herein provide for a dental attachmentassembly and method which anchors a dental appliance with an implant orother base structure, the dental attachment assembly including anabutment member attached to the implant or base structure, a retentionmember in releasable snap engagement with the abutment member, and a capsecured in a recess of the dental appliance and configured in releasableswivel engagement with the retention member to position and secure thedental appliance onto the implant. The cap includes a cavity with arounded, concave inner surface which engages with the retention member,and an interior top surface of the cavity with a concave recessextending radially along an outer periphery of the interior top surfaceof the cavity to allow for the retention member to swivel within thecap. A central portion of the interior top surface of the cavitysurrounded by the concave recess therefore protrudes vertically into thecavity to minimize vertical displacement of the retention member as itrotates within the cap.

After reading this description it will become apparent to one skilled inthe art how to implement the invention in various alternativeembodiments and alternative applications. However, although variousembodiments of the present invention will be described herein, it isunderstood that these embodiments are presented by way of example only,and not limitation. As such, this detailed description of variousalternative embodiments should not be construed to limit the scope orbreadth of the present invention as set forth in the appended claims.

The dental attachment assembly described herein simplifies the processof attaching a dental appliance to a base structure such as an implantby providing greater flexibility and movement of the dental attachmentassembly as the assembly is being positioned onto the implant. Thecreation of a concave recess extending radially along an outer peripheryof the interior top surface of the cavity allows the retention elementto rotate or swivel within the cap at a greater angle, which increasesthe allowable angle correction at which the assembly can be fitted ontothe abutment while limiting vertical displacement of the retentionelement. There are many anatomical conditions that dictate implants beplaced at various angulations which exceed the angle correctioncapabilities of current prosthetic options. This improved cap andassembly provides greater ease of use when positioning and adjusting adental appliance in a person's mouth.

A. Dental Attachment Assembly

FIG. 1A illustrates one embodiment of the dental attachment assembly 100attached with an implant 102 that may be anchored to a bone or otherbase structure (not shown) such as a tooth root. An abutment 104 of thedental attachment assembly 100 is attached to one end of the implant 102such that the abutment 104 is visible above the tissue typicallysurrounding the implant 102. A retention member 106 is then connectedwith a top portion of the abutment 104 via a releasable snap engagementor other retention means described below. A cap 108 with a rounded,concave inner surface defining a cavity is then fitted in swivelengagement over the retention member 106 to allow the cap 108 to swivelwith respect to the retention member 106 and abutment 104. The cap 108is secured in a recess of a dental appliance (as shown in FIGS. 14 and15) such that the cap 108 retains the retention member 106 which engageswith the abutment 104 when the dental appliance is being fitted onto theabutment. The engagement of the cap 108 with the retention member 106defines a swivel joint which permits the cap 108 and thus the dentalappliance to swivel with respect to the retention member 106, abutment104 and implant 102.

As shown in FIG. 1A and more clearly in the isometric views in FIG. 1Band FIG. 1C, in one embodiment, an interior top surface of the cap 108is configured with a concave recess 110 extending radially along anouter periphery of the interior top surface of the cavity. The concaverecess 110 allows the cap 108 to swivel at a much greater angle withrespect to the retention member 106 and abutment 104, which makes iteasier for a person to secure the dental appliance onto the abutment104. A central portion 112 of the interior top surface of the cap 108protrudes vertically into the cap cavity and minimizes verticaldisplacement between the retention member 106 and the cap 108 that wouldhave occurred without the presence of the central portion 112. In thisexemplary embodiment, the cap is approximately 1.9 millimeters inheight, although one of skill in the art will appreciate that thedimensions of the cap may vary.

In the embodiment illustrated in FIG. 1A, the retention member 106 isretained by a skirt (or side wall) that projects from one end of the cap108 for releasable engagement of the retention member 106 with the cap108, as disclosed in U.S. Pat. No. 6,981,871, incorporated herein byreference in its entirety. The outer locating surface of the abutment104 has at least two axially spaced retention surfaces for mating, snapengagement with corresponding spaced snap engagement formations on theinner surface of the retention member 106, to provide a stacked,external retention between the abutment 104 and retention member 106.

B. Cap Design

FIG. 2 illustrates a side cutout view of the cap 108 and retentionmember 106 in a non-swiveled position, which more clearly illustrateshow the retention member 106 fits within the cavity of the cap 108 whenno swiveling has occurred. The retention member 106 is in contact withthe central portion 112 of the interior top surface of the cap 108.Outer side walls of the retention member 106 are generally curved tomatch the curved surface of the inner side walls of the cap 108, andthey may be in direct contact at a portion of the side walls at any oneposition to allow for ease of swivel without an excessive amount offriction.

In one embodiment, the concave recess 110 is specifically designed witha curvature 114 which may be formed using a series of consecutivetangent circular arcs formed from multiple circles of varying radii, asillustrated in FIG. 3 and FIG. 4. In the embodiment illustrated herein,circles A, B, and C represent portions of the tangent circular arcs usedto derive the curve 114, although any plurality of circles may be used.The circles A, B, and C are arranged from large-to-small diameter from abottom portion 108B of the cap to a top portion 108A of the cap to formthe varying angles of the curve 114. As illustrated in FIG. 5, the curve114 is designed to optimize the swivel of the cap 108 around theretention member 106 while maintaining engagement of the retentionmember 106 within the cap 108. Varying diameters of each of the circlesmay be used as long as the diameters are arranged from large-to-smallfrom a bottom-to-top direction along the interior side wall of the cap.In the exemplary embodiment of FIG. 3, the concave recess 110 is formedfrom circles A, B, and C with diameters of 0.067, 0.083 and 0.186inches, respectively (i.e. radii of curvature of 0.034, 0.042 and 0.093inches, respectively). Circle C has a diameter which intersects theconcave recess 110 on an opposing side of the cap, which thereforedefines the diameter of the cap cavity. Each curvature of each circleintersects with a different portion of the concave recess 110 to form acurved surface 114 of varying degrees of curvature, as shown in FIG. 4.

FIG. 5 illustrates one embodiment of the retention member 106 andabutment 104 in a fully swiveled position within the cap 108, where aportion of the retention member 106 has swiveled into the concave recess110 in the cap 108. The opposing side of the retention member 106 hasswiveled downward to the point that it is still retained within the cap108, which illustrates the complete range of swivel of the cap 108 inone direction. In this embodiment, the range of swivel S isapproximately 30 degrees with a cap having a diameter D of approximately5.4 millimeters (mm) and a height H of approximately 2.3 mm, althoughone of skill in the art will appreciate that these dimensions may bevaried and still achieve the same degree of rotation. The range ofrotation may reasonably extend to approximately 32 degrees and could beextended up to approximately 40 degrees if the dimensions of the cap,retention member and abutment are altered to allow for greaterrotation—for example by increasing the height of the cap and reducingthe diameter of the abutment.

FIG. 6 illustrates a series of drawings of the cap 108 and retentionmember 106 as the retention member 106 begins to swivel from anon-swiveled position to a fully-swiveled position, and FIG. 7illustrates a side view illustration of the complete dental attachmentassembly in the fully-swiveled position. With the cap 108 inserted intoa recess of a dental appliance, the amount of swivel is thereforetranslated to the dental appliance as the dental appliance is beingattached to the assembly, allowing for a great deal of flexibility as adental professional or the patient attaches the appliance to theabutment.

C. Alternative Assemblies

FIG. 8 illustrates an alternate embodiment of the dental attachmentassembly with an abutment 104 and retention member 106B which areengaged using a snap engagement between the external surface of theabutment 104 and the internal surface of the retention member 106B. Inthis embodiment, the cap 108 retains the radial concave recess 110, butthe abutment 104 has only one retention surface on the outer portion ofthe abutment for mating with the corresponding annular concavity on theretention member 106B. The cap 108 therefore still provides the addedrotational flexibility with the retention member 106B and abutment 104even though the retention mechanism is different.

FIG. 9 illustrates another alternative embodiment where the abutment 104is provided with axially-spaced retention surfaces, although theretention member 106B is not configured with corresponding annulargrooves. Nevertheless, the retention member 106B is still capable ofretaining the abutment 104 and providing for full rotation within thecap 108 within the concave recess 110.

FIG. 10A illustrates the design of the curvature of an outer curvedsurface 118 of the retention member 106B without annular grooves forretaining the abutment, while FIG. 10B illustrates the design of thecurvature of an outer curved surface 120 of the retention member 106with annular grooves for retaining the abutment. The measurementsprovided demonstrate that various geometry configurations can bedesigned so that the retention member will swivel within the cap. Thedesign can be optimized to provide for movement of the retention memberin the cap free from friction or can be designed with a small amount ofresistance, while still allowing for swiveling within the cap. In FIG.10A, the outer curved surface 118 of retention member 106B is configuredfrom a circle E with a diameter of 0.060 inches and a circle F with adiameter of 0.187 inches. In FIG. 10B, the outer curved surface 120 ofretention member 106 is configured from a circle G with a diameter ofapproximately 0.040 inches, a circle H with a diameter of approximately0.074 inches, and a circle I with a diameter of approximately 0.186inches. The slight variances in measurement illustrate that bothconfigurations of retention members are capable of fitting within thecap and achieving the same degree of swivel provided by the concaverecess 110.

FIG. 11 illustrates a dental attachment assembly 100 of a smaller sizethan the embodiment illustrated in FIG. 1A and FIG. 5. Despite thesmaller size, the angle of swivel S is still approximately 30 degrees,indicating that different sized attachment assemblies may be made withthe same properties for use in different sections of the mouth wherelarger assemblies may be impractical. FIG. 12 illustrates a side viewillustration of the smaller dental attachment assembly 100 in thefully-swiveled position.

D. Method of Use

FIG. 13 illustrates one embodiment of a method of attaching a dentalappliance to an implant using the dental attachment assembly describedherein. In a first step 1302, an abutment is secured to an implant orother root structure that will support the dental appliance. Next, anon-swiveling retention member is inserted into the cap (step 1304), andthis assembly is then attached to the abutment in step 1306. In step1308, the dental appliance is modified with a recess placed in theappropriate position to accept the non-swiveling retention member andcap assembly in preparation for attachment, and in step 1310, the cap isbonded into the recess in the dental appliance. In step 1312 thenon-swiveling retention member is removed from the cap and a swivelingretention member is inserted into the cap. In step 1312, the dentalappliance may be engaged onto the abutment by the snap engagement of theretention member onto the abutment and may be swiveled or rotated intoplace through use of the swivel joint between the cap and retentionmember, which is further enhanced by the concave recess within the cap.

FIG. 14 is a side view illustration of the dental attachment assemblyafter securing a dental appliance 120 with the cap 108 in the abutment104 attached with the implant 102 in a patient's mouth 122. FIG. 15 is aside view illustration of the method of attaching the dental appliance120 to the cap 108 and retention member 106, and subsequently fittingthe dental appliance assembly onto the abutment 104 and implant 102.

By providing the cap with the concave recess in combination withmultiple configurations of the dental attachment assembly, any dentalattachment assembly is provided with an increased allowable anglecorrection when attaching a dental appliance to an implant, simplifyingthe attachment process and reducing the risk of damage to the componentparts from misalignments and wear from use at high angulations.

The above description of the disclosed embodiments is provided to enableany person skilled in the art to make or use the invention. Variousmodifications to these embodiments will be readily apparent to thoseskilled in the art, and the generic principles described herein can beapplied to other embodiments without departing from the spirit or scopeof the invention. Thus, it is to be understood that the description anddrawings presented herein represent a presently preferred embodiment ofthe invention and are therefore representative of the subject matterwhich is broadly contemplated by the present invention. It is furtherunderstood that the scope of the present invention fully encompassesother embodiments that may become obvious to those skilled in the artand that the scope of the present invention is accordingly not limited.

What is claimed is:
 1. A cap of a dental attachment assembly,comprising: a generally cup shaped member having a central longitudinalaxis, a top wall and an annular side wall extending away from the topwall, the top wall and side wall having an outer surface shaped toengage with a recess in a dental appliance and a rounded, concave innersurface defining a cavity configured for swivel engagement with aretention member adapted for non-swivel engagement over an outerlocating surface of an abutment member attached to a tooth root,implant, or adjacent tooth and having a central longitudinal axis; thetop wall having an interior top surface with a concave recess extendingradially in an annular path along an outer annular peripheral portion ofthe interior top surface, the concave recess forming a curve having afirst radius of curvature; and the curve of the concave recesscontinuing along at least part of the inner surface of the side walltowards an open end of the rounded, concave inner surface of the cavity;and wherein the curve is configured to provide swivel engagement withthe retention member between a non-swiveled position in axial alignmentwith the central longitudinal axis of the retention member and afully-swiveled position in which the central longitudinal axis of thecavity is at an angle to the central longitudinal axis of the retentionmember.
 2. The cap of claim 1, further comprising a central portion ofthe top surface which protrudes vertically into the cavity, theprotruding central portion adapted to contact a central portion of anopposing surface of the retention member in the non-swiveled position.3. The cap of claim 1, wherein the curve of the concave recess and innersurface of the side wall of the cavity comprise a plurality ofconsecutive tangent circular arcs having different radii of curvaturealong the length of the curve from the top wall along the side wall; 4.The cap of claim 3, wherein the radii of curvature of the series ofconsecutive tangent circular arcs increase in size from the interior topsurface towards an open end of the rounded, concave inner surface of thecavity.
 5. The cap of claim 4, wherein the radii of curvature of theseries of consecutive tangent circular arcs increase in size from theinterior top surface to the open end of the rounded, concave innersurface of the cavity.
 6. The cap of claim 5, wherein there are threeconsecutive tangent circular arcs along the curve of the concave innersurface of the cavity.
 7. The cap of claim 6, wherein the consecutivetangent circular arcs have radii of 0.034, 0.042 and 0.093 inches,respectively.
 8. The cap of claim 1, wherein an outer diameter of thecap is approximately 5.4 millimeters (mm) and a height of the cap isapproximately 2.3 mm.
 9. The cap of claim 1, wherein the swivelengagement of the concave recess of the cap with respect to theretention member between the non-swiveled and fully-swiveled position isup to approximately 30 degrees.
 10. The cap of claim 1, wherein theconcave recess in the interior top surface of the cap is adapted toprovide a space between the interior top surface and an opposing firstend of the retention member in the non-swiveled position and to engagean opposing outer surface portion of the retention member in thefully-swiveled position.